Gema Food Coating

Your global partner for high quality powder coating

Electrostatic application is ideal for customers who expect a consistent application of a wide variety of powder ingredients and want to achieve high-quality coatings for their food products. The key benefits of this new technology are a precise application of the ingredients, improved powder adhesion, quality enhancements, cost-effectiveness and better process control.Electrostatic application technology, which has been used in the industrial finishing market for decades, is now revolutionizing the food business. Gema, for over 40 years the worldwide leading manufacturer of equipment

and systems for electrostatic powder coating, has now developed an innovative technology that simplifies and improves the application of powder ingredients on cakes, biscuits, donuts, snacks, chips and a number of other food products.Traditional gravity systems have been used for a long time for the application of powder ingredients on food products. Their limitations and problems are well-known, for example the requirement of a high humidity on the piece to ensure a sufficient adhesion, unstable product quality due to uneven powder distribution, ambient contamination due to airborne powder migration to the working area, high maintenance and sanitization costs

both in the application stage and in the subsequent process steps until final packaging.With the new electrostatic application technology by Gema these problems are solved and significant improvements in terms of product quality and application process stability are easily achieved.The main characteristics of Gema’s coating systems are their extreme flexibility and versatility. The electrostatic technology offers very broad application possibilities for food manufacturers and processing companies. It is possible to apply a large variety of powder ingredients with diverse textures, particle sizes and coating requirements,

Electrostatic application: a revolutionary technology for the application of powder ingredients


A

F

B

HC

E

G

I

KD

examples include salt, seasoning, every kind of sugar, cocoa, starch, flour. Gema design and supply complete food coating lines, powder recovery systems, and offer upgrades and retrofit solutions to existing systems, examples include upgrading drum coating systems with electrostatic applicators, this allows these traditional systems to benefit from performance improvements available from electrostatic coating.The electrostatic application technology also promotes product innovation: various customers have used this technology to develop and launch new appealing products that would simply not be possible with traditional food coating technologies.

Working principle of the electrostatic applicationElectrostatic powder application is a coating process that employs electrostatic charges to improve the application of powder particles onto the products.Corona guns are used to apply an electrical charge to the powder particles that are sprayed towards the objects to coat (figure 1). The high voltage electrode on the tip of the gun creates an electric field and emits charges that are transferred to the powder particles. The powder particles are attracted by the grounded objects and remain attached to them also after the application process.

Complete coating systems offer all the advantages of powder containment and powder recirculation The electrostatic application takes place in a fully automated powder booth provided with an exhaust system that prevents the powder from escaping to the ambient (figure 2). The powder booth’s recovery system captures and continuously recirculates the powder, which can be immediately re-used.

Electrostatic technology can also be easily integrated in existing drum systemsWith a limited investment and a quick installation time the performance of

• From the fluidized hopper (A) the injectors (B) pump the powder to the guns (C), that charge it electrostatically and apply it one the pieces.

• The over-sprayed powder deposited on the conveyor (D) is recovered and pumped back (E) to a sieving system (F) and to the fluidized hopper (A) to be immediately reused.

• The fan system (G) extracts air from the booth (H) and keeps it under depression. The powder particles in the extraction air are filtered (I) and collected in a waste container (K).

Figure 2: Electrostatic Booth

The high voltage electrode creates an electric field that guides the powder to the piece.

The charged powder particles are attracted

by the pieces to coat and remain attached to them also after the

application.

The electric field ensures a more uniform coating.

No attraction to the piece results in poor transfer efficiency and

ambient contami-nation.

Figure 1: Application Principle

Lack of control results in

uneven coating application.

Traditional gravity coating systems rely purely on gravity to dispense the coating

onto the piece.

Electrostatic Gun applies an electric charge to the

powder particles that are sprayed towards the piece.


existing drums can be dramatically improved, with a much better powder distribution on the products and a strong reduction of the airborne powder migration outside of the drum (figure 3).

Precise process control and dosing of the ingredientsAll the pneumatic and electrostatic application parameters are easily adjustable to optimize the application process. This means that thanks to Gema’s technologies it is finally possible to control more precisely the amount of powder ingredients that are applied on each product. Besides the significant material cost savings, this also allows to meet increasingly stringent labeling regulations (sugar / salt / sodium content etc.) and to better satisfy customers’ dietary expectations.

Improved and long lasting product qualityThanks to the electrostatic application it is possible to apply a more precise and uniform layer of powder ingredients on the surface of the products. This makes their aesthetical appearance much more appealing and consistent (figure 4 + 5).The electrostatic charges create a strong attraction between the powder particles and the pieces to be coated. Osmotic attraction gradually replaces the electrostatic attraction and maintains an excellent coating adhesion to the pieces for a long time after the application. The electrostatic adhesion ensures that the products maintain their consistent and appealing appearance for a long time, ready for the end-user consumption (figure 6).

Reliable and cost-effective technologyThe electrostatic technology offers a better control over the application process and much higher transfer efficiency in comparison to traditional gravity systems. This essentially means that the ingredients application is better focused on the products and less powder is wasted in the ambient (figure 7).The powder particles remain firmly attached on the pieces also during all the

Figure 5: Comparison Application Technologies with Drum System

Electrostatic Application Traditional Application

Figure 4: Comparison Application Technologies with Conveyer Belt

Figure 3: Drum System with electrostatic components

Without Electrostatic With Electrostatic

Figure 6: Results new Application Technology

Electrostatic Application Traditional Application

Gema Switzerland GmbHMövenstrasse 17 | 9015 St.Gallen | SwitzerlandT +41 71 313 83 00 | F +41 71 313 83 83www.gemafoodcoating.com

process steps following the application (transportation, baking, packaging etc.). This brings great material cost savings and also allows a significant reduction of cleaning and sanitization time as well as maintenance costs.

Positive experience in practiceA growing number of customers using electrostatic application systems in various markets can confirm the great advantages that are offered by this revolutionary technology. “We thoroughly tested Gema’s technology across a range of rice snacks and chips and discovered many benefits from this technology” explained the head of the production department of one of the largest European food companies. “Through this technology we are able to achieve a constant powder application, an even surface quality and reproducible coating results. This guarantees that our products offer a consistently high quality, which is essential to us and to our consumers”.“There is a growing customer interest for our coating solutions in the bakery, snack, meat, cheese, and other markets. At our Swiss R&D laboratory we continue to research and develop new applications and make discoveries and disclose new opportunities in food coating: Our facilities offer our customers the opportunity to test new powder ingredients, develop new products, and well as working collaboratively to optimise their manufacturing processes.” expalined Marco Spada, food market manager at Gema. “This technology presents a real opportunity to revolutionise the food market for many years to come.”

March 2016

More information under:www.gemafoodcoating.com

Figure 7: Precise application